// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_CHILD_FILEAPI_WEBFILEWRITER_BASE_H_
#define CONTENT_CHILD_FILEAPI_WEBFILEWRITER_BASE_H_

#include <stdint.h>

#include "base/files/file.h"
#include "content/common/content_export.h"
#include "third_party/WebKit/public/platform/WebFileWriter.h"
#include "url/gurl.h"

namespace blink {
class WebFileWriterClient;
}

namespace content {

class CONTENT_EXPORT WebFileWriterBase
    : public NON_EXPORTED_BASE(blink::WebFileWriter) {
public:
    WebFileWriterBase(const GURL& path, blink::WebFileWriterClient* client);
    ~WebFileWriterBase() override;

    // WebFileWriter implementation
    void truncate(long long length) override;
    void write(long long position, const blink::WebString& id) override;
    void cancel() override;

protected:
    // This calls DidSucceed() or DidFail() based on the value of |error_code|.
    void DidFinish(base::File::Error error_code);

    void DidWrite(int64_t bytes, bool complete);
    void DidSucceed();
    void DidFail(base::File::Error error_code);

    // Derived classes must provide these methods to asynchronously perform
    // the requested operation, and they must call the appropiate DidSomething
    // method upon completion and as progress is made in the Write case.
    virtual void DoTruncate(const GURL& path, int64_t offset) = 0;
    virtual void DoWrite(const GURL& path,
        const std::string& blob_id,
        int64_t offset)
        = 0;
    virtual void DoCancel() = 0;

private:
    enum OperationType {
        kOperationNone,
        kOperationWrite,
        kOperationTruncate
    };

    enum CancelState {
        kCancelNotInProgress,
        kCancelSent,
        kCancelReceivedWriteResponse,
    };

    void FinishCancel();

    GURL path_;
    blink::WebFileWriterClient* client_;
    OperationType operation_;
    CancelState cancel_state_;
};

} // namespace content

#endif // CONTENT_CHILD_FILEAPI_WEBFILEWRITER_BASE_H_
